Portfolio » Pond liner repair – fixing a pond leak, Bristol


There are many reasons why your pond water level can be going down, here we look at a pond leak from a damaged liner, probable causes and how we complete a repair.

What can cause a pond leak?

Liner leaks can be the result of a cracked, torn, cut, scratched, punctured or otherwise damaged liner or a low liner edge. When a liner is exposed to the sun (UV rays) it can perish and deteriorate to the point of cracking, this is more common in older liners. This occurs predominantly on the top of a fold (especially if it is flexing) but may be all over in a crazed or linear pattern. A common cause of liner leak is a lowered edge; as a result of poor planning, physical impact or ground movement. The most common liner problem we come across is a puncture of some kind. The cause can often be identified and varies from accidental damage; directly e.g. stabbed with a garden fork or indirectly e.g. dropped something into the pond or on to the liner. Animal damage; often a v shaped mark(s) where a pet or wild animal  has been for a dip or fallen in and scrabbled back out leaving a series of claw marks or a e.g. heron has been hunting the pond life; leaving  individual stab marks. Plants are another puncture cause, especially species like bamboo’s and grasses with persistent sharp and strong rhizomes or roots. Trees can also cause damage with falling branches and penetrating roots. Most species roots will follow the liner/underlay.

What equipment do we use?

Gloves, Cloths and sponges to clean and dry the liner, A spare piece of liner, Some pond liner repair tape, Scissors, A heat gun,

CAUTION must be taken when using electricity, working near water, using hot tools or sharp tools. For further information see http://www.hse.gov.uk

How do we complete a pond liner repair?

  • First we must find the hole: Top the pond up and let it drop back down to its lowest level. It can help to mark this level with some pencil/crayon so that we can find it easily. If there is one hole then the water line or close by is where you will find it. It will be much easier to identify holes if the liner has dried as it shows greater contrast.
  • Cleaning: now we clean around the hole with a sponge.
  • Drying: we dry the surrounding area with a cloth including  above. we use a heat gun to further dry the area as required.
  • Making a patch: now we take the pond liner repair tape and peel off one side of the backing strip. Next place some spare liner onto the tape and it will bond. Cut a patch from the liner and tape; rounded edges catch less than straight ones.
  • Performing the patching:  first we peel off the remaining backing strip from the patch and rest it down on the liner side. we take the heat gun and warm the area around the hole where the patch will go. This does not take long and is performed on a low setting and from some distance. Then we place the patch over the hole and press down firmly with a gloved hand. Next we apply more heat from the heat gun over the patch, this warms the glue and forms a bond. Finally we apply further pressure to the patch to ensure a good seal.
  • Once this repair has cured you can top up or refill the pond, any further holes can be identified and repaired by repeating the process.
  • It is often worth having a pond clean and equipment service at the same time as performing a repair.

If you need a pond liner assessed, a pond liner repair or a pond re-lined in the Bristol & Bath region please contact us at Aquaflora Landscapes and we will be happy to help.